<template>      
   <Person v-if="isShow"/>
</template>

<script lang="ts"  setup name="App">  //脚本标签
// JS或TS
  import Person from './components/Person.vue'
  import {ref,onMounted} from 'vue'

  let isShow = ref(true)

  //挂载完毕
  onMounted(()=>{
        console.log("父挂载完毕")
    })

//   export default{
//   name:'App',//组件名
//   components:{Person}//注册组件
// }
</script>